1. The Field of the Invention
This invention relates to book bindings and more particularly to that class adapted to provide security against tampering by threading the pages together with a ribbon and sealing the ribbon ends together to a cover page of the book.
2. Description of the Prior Art
The prior art abounds with disclosures of document security systems employing pages linked by a threading ribbon with the ends of the ribbon sealed together. Original United States patents are currently sealed by this method, employing a foil seal applied with glue. A simple dangling seal system employing lead for the seal material and a wire to bind the pages together, or alternatively a wax seal securing the ends of a threading cord are disclosed by U.S. Pat. No. 593,125, issued to A. Rosedale on Nov. 2, 1897 entitled "Mileage Book and Coupon Ticket Protector." A similar lead seal and wire security system for a block or stack of lottery tickets is disclosed by U.S. Pat. No. 3,307,858, issued to S. Sanden on Mar. 7, 1967. U.S. Pat. No. 2,283,898, issued to S. Arico on May 26, 1942, discloses a similar sealing system employing a threaded cord with the ends sealed down to a page by means of sealing wax. U.S. Pat. No. 2,832,307, issued to J. Cavallero on Apr. 29, 1958, discloses the use of thermosetting plastic to bond together the ends of a group of ribbon book markers for removable placement in between the leaves of a book. This patent, however, neither discloses nor claims use of thermosetting plastic as an adjunct to ribbon sealed document security systems, or as a means of sealing a single ribbon into a closed loop for permanent attachment to a book.
Seals made between adjacent layers of conventional materials are only a minor hindrance to determined efforts to separate them. Soft metal seals, such as the lead seal employed in conjunction with a wire, are easily pried away from the wire, whereupon the documents bound thereby are vulnerable to unauthorized page replacement, after which the soft metal seal may once again be crimped together over the ends of the wire. Thermoplastic materials, such as some types of wax, form equally vulnerable seals in that such seals can be easily melted and lifted, typically with a hot knife, the resealing being subsequently accomplished by a simple undetectable reheating operation. The known art suffers from the lack of a seal material that discourages attempts to tamper with the sealed documents by undergoing irreversible changes in its mechanical properties resulting from efforts to open or "lift" the sealed materials, and whose mechanical condition and physical appearance are difficult to reproduce if the seal is deliberately or accidentally broken in the tampering process.